Whakaoti i te 20^2-ab-2b^2=39-3^b+3

$$20 ^ { 2 } - a b - 2 b ^ { 2 } = 39 - 3 ^ { b + 3 }$$

Whakaoti mō a

$$a=\frac{361+27\times 3^{b}-2b^{2}}{b}$$

$$b\neq 0$$

Ngā Upane mō te Whakaoti Whārite Rārangi

Tātaihia te 20 mā te pū o 2, kia riro ko 400.

$$400-ab-2b^{2}=39-3^{b+3}$$

Tangohia te 400 mai i ngā taha e rua.

$$-ab-2b^{2}=39-3^{b+3}-400$$

Me tāpiri te 2b^{2} ki ngā taha e rua.

$$-ab=39-3^{b+3}-400+2b^{2}$$

Tangohia te 400 i te 39, ka -361.

$$-ab=-361-3^{b+3}+2b^{2}$$

He hanga arowhānui tō te whārite.

$$\left(-b\right)a=2b^{2}-3^{b+3}-361$$

Whakawehea ngā taha e rua ki te -b.

$$\frac{\left(-b\right)a}{-b}=\frac{2b^{2}-27\times 3^{b}-361}{-b}$$

Mā te whakawehe ki te -b ka wetekia te whakareanga ki te -b.

$$a=\frac{2b^{2}-27\times 3^{b}-361}{-b}$$

Whakawehe -361-27\times 3^{b}+2b^{2} ki te -b.

$$a=\frac{27\times 3^{b}+361}{b}-2b$$